Grinding wheel and holder



July 14, 1931. H. asAcH 8 GRINDING WHEEL AND HOLDER Filed April 14, 1926 INE'NTOR Patented July 14, 1931 UNITED STATES PATENT OFFICE HOBART C. BEACH, OF COVINGTON, KENTUCKY, ASSIGNOB TO THE. CARBORUNDUBI GOMPANY, OF NIAGARA FALLS, NEU YORK, A CORPORATION OF PENNSYLVANIA GRINDING WHEEL AND HoLnEn Application filed April 14,

The present invention relates to the art of grinding and more particularly to a grinding wheel and holder therefor and to a novel method of securing the wheel in the holder. The invention is for an improvement on the invention disclosed in my earlier filed application, Serial No. 39011. dated June :23, 1925 ne Patent No. 1,710,528, dated April 23, L:

For grinding certain classes of work, such as the inside surfaces of bathtubs and similar castings for the purpose of preparing them for the enameling process, the grinding wheel is mounted on the end of a. flexible. operating shaft in order to enable the operator to move the wheel about so as to smooth such surfaces of a casting as require grinding. In thisoperation both the end face and the periphery of the stone is used.

In my earlier filed application above referred to, I have shown a holder adapted to co-operate with a projecting flange on one face of the grinding wheel. \Vhile the con: struction shown in the said application constituted a considerable improvement, the device had certain objections among which was the increased weight of the holder over holders which had previously been used.

According to the present invention it is proposed to provide a holder of simple construction which is firmly secured to the stone and which is relatively light, and at the same time is semirigid, thereby allowing the wheel to accommodate itself to the high spots on the casting so that the wheel may be more easily held against the work and will have less tendency to jump away from the work, particularly when a high spot on the work is encountered.

The invention may be readily understood by reference to the accompanying drawings which illustrate a preferred embodiment of the invention but it will be understood that various changes and modifications may be made in the detail construction thereof within the spirit and contemplation of the invention.

1926. Serial No; 101,926.

section through the grinding wheel and holder;

Figure 2 represents a plan view of the wheel and holder.

In the drawings, 2 designates an abrasive grinding wheel having a working face 3 and a grinding periphery 4 and having an annular projection .5 on its other face which is slightly undercut around its periphery as indicated at 6. Fitted over the projecting flange 5, which flange is in the nature of a reduced hub portion is a holder formed of a single piece of metal 7 withan inwardly turned edge 8 that fits over the undercut edge 6 of the reduced hub portion. The inwardly turned flange 8 preferably has an outwardly extending lip 9 extending there around. The holder is preferably made of'pressed metal of about No. 12 gauge so that it is not entirely rigid but is slightly flexible. Near the outer edge of the disk portion 7 is a channel 10. One or more openings 11 may he provided in the disk through which molten sulphur may be poured for the purpose of securing the holder to the stone.

The disk 7 has a central opening 12 therein through which the end of the driving shaft 13 passes and the disk is secured to the driv' ing shaft in any suitable manner. I have illustrated this connection as being provided by means of pins 14 carried in a washer member 15 which is clamped against the inner surface of the disk by a nut 16 on .the end of the shaft 13. The pins 14 pass through the disk and. their inner terminals are received in the metal hub member 17 The disk-like holder is fitted over the hub portion 5 of the wheel as shown in Figure 1, after which molten sulphur is poured through the holes 11, the disk being maintained in a central position with respect to the wheel during this time. The sulphur flows around the channel 10 and into the space and between the intur'ned metal flange 8 and the undercut periphery (3 of the reduced hub portion. This sulphur also flows between the lip 9 and the face of the stone so as to insure of the stone having an even support on the lip 9. When the sulphur cools it serves to effectively cement the stone in the the center of torsional forcel; ;exc-rted by the grindin operation. Betweenthepointwhere the holdler grips the wheel,and the point where the shaft grips the holder, the holder, due

' to its being made of sheet steel, is semi-rigid and has a certain degree of elasticity.

It has been found in actual practice when a wheel supported in this manner is passed 7 over the surface to be ground, the flexible mounting allows the wheel to accommodate itself to a certain extent to the inequalities in the work, so that the Wheel stays close to or hugs the work instead of jumping off at the high spots. It has been found that wheels mounted in this manner will grind about 40% more bathtubs than the cup-like stones heretofore generally used for this purpose. Part of this increased efliciency is due to the fact that a greater portion of the stone can be used than is possible with stones of the cup-shaped type heretofore used wherein a large portion of the stone had to be thrown away because of the manner in which the stone is secured to its operating shaft. This increase in efiiciency is also attributed to the semi-rigid mounting provided by the pressed metal holder.

It will be seen that with the construction herein described. the periphery as well as the face 3 of the stone can be used and the stone can be worn down to a very considerable" extent before the holder will interfere in any manner with the operation of the stone. The holder has certain further advantages in that it will also tend to reduce the danger to which the operator is subject by reason of the rapidly rotating heel cracking and flying to pieces, as the mounting herein provided tends to support and retain parts of a cracked wheel.

I claim:

1. A combination with a grinding wheel having a reduced hub portion, of a holder formed of pressed sheet metal, said holder having a disk portion in which is a channel, an inwardly turned flange around the disk portion outside the channel, and a binding material filling the channel and the space between the reduced hub portion and the inwardly turned flange, said disk having a hole therein through which the binding material may be poured into the said annular channel.

2. In a grinding wheel assembly, a grinding wheel having one face and its periphery adapted to be used for grinding, said wheel having a projecting portion of reduced diameter on its other face, a drive shaft, and a semi-rigid driving connection of a diameter less than that of the wheel between the shaft and said projection on the wheel.

3. In a grinding wheel assembly, a grinding wheel having one face and its periphery adapted to be used for grinding, the wheel having a projecting portion on its other face of less diameter than the diameter of the wheel, a driving shaft, a semi-rigid holder of less diameter than the diameter ofthe wheel carried on the driving shaft and embracing the projecting portion of the wheel, and binding material interposed between the wheel and the holder.

4. The combination with a grinding wheel adapted for both peripheral and face grinding and having an annular undercut projection on one thereof interme-\ diate the periphery and the core of the wheel, of a pressed sheet metal disk which contacts directly with a portion cf. the back of said wheel adjacent the core, fte outer portion of said disk having an S-shaped cross section which is cemented around the annular projection of the wheel, whereby the metal disk supports the grinding wheel in both axial and radial directions.

In testimony whereof I have hereunto set my hand.

HOBART C. BEACH. 

